/*
 * @author zz85 / https://github.com/zz85
 *
 * Ascii generation is based on http://www.nihilogic.dk/labs/jsascii/
 * Maybe more about this later with a blog post at http://lab4games.net/zz85/blog
 *
 * 16 April 2012 - @blurspline
 */

THREE.AsciiEffect = function ( renderer, charSet, options ) {

    // its fun to create one your own!

    charSet = ( charSet === undefined ) ? ' .:-=+*#%@' : charSet;

    // ' .,:;=|iI+hHOE#`$';
    // darker bolder character set from https://github.com/saw/Canvas-ASCII-Art/
    // ' .\'`^",:;Il!i~+_-?][}{1)(|/tfjrxnuvczXYUJCLQ0OZmwqpdbkhao*#MW&8%B@$'.split('');

    if ( !options ) options = {};

    // Some ASCII settings

    var bResolution = !options['resolution'] ? 0.15 : options['resolution']; // Higher for more details
    var iScale = !options['scale'] ? 1 : options['scale'];
    var bColor = !options['color'] ? false : options['color']; // nice but slows down rendering!
    var bAlpha = !options['alpha'] ? false : options['alpha']; // Transparency
    var bBlock = !options['block'] ? false : options['block']; // blocked characters. like good O dos
    var bInvert = !options['invert'] ? false : options['invert']; // black is white, white is black

    var strResolution = 'low';

    var width, height;

    var domElement = document.createElement('div');
    domElement.style.cursor = 'default';

    var oAscii = document.createElement("table");
    domElement.appendChild( oAscii );

    var iWidth, iHeight;
    var oImg;

    this.setSize = function ( w, h ) {

        width = w;
        height = h;

        renderer.setSize( w, h );

        initAsciiSize();

    };


    this.render = function ( scene, camera ) {

        renderer.render( scene, camera );
        asciifyImage( renderer, oAscii );

    };

    this.domElement = domElement;


    // Throw in ascii library from http://www.nihilogic.dk/labs/jsascii/jsascii.js

    /*
     * jsAscii 0.1
     * Copyright (c) 2008 Jacob Seidelin, jseidelin@nihilogic.dk, http://blog.nihilogic.dk/
     * MIT License [http://www.nihilogic.dk/licenses/mit-license.txt]
     */

    function initAsciiSize() {

        iWidth = Math.round( width * fResolution );
        iHeight = Math.round( height * fResolution );

        oCanvas.width = iWidth;
        oCanvas.height = iHeight;
        // oCanvas.style.display = "none";
        // oCanvas.style.width = iWidth;
        // oCanvas.style.height = iHeight;

        oImg = renderer.domElement;

        if ( oImg.style.backgroundColor ) {

            oAscii.rows[0].cells[0].style.backgroundColor = oImg.style.backgroundColor;
            oAscii.rows[0].cells[0].style.color = oImg.style.color;

        }

        oAscii.cellSpacing = 0;
        oAscii.cellPadding = 0;

        var oStyle = oAscii.style;
        oStyle.display = "inline";
        oStyle.width = Math.round(iWidth/fResolution*iScale) + "px";
        oStyle.height = Math.round(iHeight/fResolution*iScale) + "px";
        oStyle.whiteSpace = "pre";
        oStyle.margin = "0px";
        oStyle.padding = "0px";
        oStyle.letterSpacing = fLetterSpacing + "px";
        oStyle.fontFamily = strFont;
        oStyle.fontSize = fFontSize + "px";
        oStyle.lineHeight = fLineHeight + "px";
        oStyle.textAlign = "left";
        oStyle.textDecoration = "none";
    }


    var aDefaultCharList = (" .,:;i1tfLCG08@").split("");
    var aDefaultColorCharList = (" CGO08@").split("");
    var strFont = "courier new, monospace";

    var oCanvasImg = renderer.domElement;

    var oCanvas = document.createElement("canvas");
    if (!oCanvas.getContext) {
        return;
    }

    var oCtx = oCanvas.getContext("2d");
    if (!oCtx.getImageData) {
        return;
    }

    var aCharList = (bColor ? aDefaultColorCharList : aDefaultCharList);

    if (charSet) aCharList = charSet;

    var fResolution = 0.5;

    switch ( strResolution ) {

        case "low" : 	fResolution = 0.25; break;
        case "medium" : fResolution = 0.5; break;
        case "high" : 	fResolution = 1; break;

    }

    if ( bResolution ) fResolution = bResolution;

    // Setup dom

    var fFontSize = (2/fResolution)*iScale;
    var fLineHeight = (2/fResolution)*iScale;

    // adjust letter-spacing for all combinations of scale and resolution to get it to fit the image width.

    var fLetterSpacing = 0;

    if ( strResolution == "low" ) {

        switch (iScale) {
            case 1 : fLetterSpacing = -1; break;
            case 2 :
            case 3 : fLetterSpacing = -2.1; break;
            case 4 : fLetterSpacing = -3.1; break;
            case 5 : fLetterSpacing = -4.15; break;
        }

    }

    if ( strResolution == "medium" ) {

        switch (iScale) {
            case 1 : fLetterSpacing = 0; break;
            case 2 : fLetterSpacing = -1; break;
            case 3 : fLetterSpacing = -1.04; break;
            case 4 :
            case 5 : fLetterSpacing = -2.1; break;
        }

    }

    if ( strResolution == "high" ) {

        switch (iScale) {
            case 1 :
            case 2 : fLetterSpacing = 0; break;
            case 3 :
            case 4 :
            case 5 : fLetterSpacing = -1; break;
        }

    }


    // can't get a span or div to flow like an img element, but a table works?


    // convert img element to ascii

    function asciifyImage( canvasRenderer, oAscii ) {

        oCtx.clearRect( 0, 0, iWidth, iHeight );
        oCtx.drawImage( oCanvasImg, 0, 0, iWidth, iHeight );
        var oImgData = oCtx.getImageData(0, 0, iWidth, iHeight).data;

        // Coloring loop starts now
        var strChars = "";

        // console.time('rendering');

        for (var y=0;y<iHeight;y+=2) {
            for (var x=0;x<iWidth;x++) {
                var iOffset = (y*iWidth + x) * 4;

                var iRed = oImgData[iOffset];
                var iGreen = oImgData[iOffset + 1];
                var iBlue = oImgData[iOffset + 2];
                var iAlpha = oImgData[iOffset + 3];
                var iCharIdx;

                var fBrightness;

                fBrightness = (0.3*iRed + 0.59*iGreen + 0.11*iBlue) / 255;
                // fBrightness = (0.3*iRed + 0.5*iGreen + 0.3*iBlue) / 255;

                if (iAlpha == 0) {
                    // should calculate alpha instead, but quick hack :)
                    //fBrightness *= (iAlpha / 255);
                    fBrightness = 1;

                }

                iCharIdx = Math.floor((1-fBrightness) * (aCharList.length-1));

                if (bInvert) {
                    iCharIdx = aCharList.length - iCharIdx - 1;
                }

                // good for debugging
                //fBrightness = Math.floor(fBrightness * 10);
                //strThisChar = fBrightness;

                var strThisChar = aCharList[iCharIdx];

                if (strThisChar===undefined || strThisChar == " ")
                    strThisChar = "&nbsp;";

                if (bColor) {
                    strChars += "<span style='"
                        + "color:rgb("+iRed+","+iGreen+","+iBlue+");"
                        + (bBlock ? "background-color:rgb("+iRed+","+iGreen+","+iBlue+");" : "")
                        + (bAlpha ? "opacity:" + (iAlpha/255) + ";" : "")
                        + "'>" + strThisChar + "</span>";
                } else {
                    strChars += strThisChar;
                }
            }
            strChars += "<br/>";
        }

        oAscii.innerHTML = "<tr><td>" + strChars + "</td></tr>";

        // console.timeEnd('rendering');

        // return oAscii;
    }

    // end modified asciifyImage block

};
